1. Field of the Invention
The present invention relates to a linear compressor, more particularly, which is capable of preventing an exhale spring and an exhale cover from being abraded and from being transformed, caused by a load from the exhale spring.
2. Description of the Related Art
Generally, a linear compressor is a machine to inhale, to compress, and to discharge fluid by linearly reciprocating a piston within a cylinder, by means of linear driving force of a linear motor.
FIG. 1 shows the linear compressor, in accordance with the prior art, and FIG. 2 shows a structure of an exhale part of the linear compressor, in accordance with the prior art.
In a hermetic casing 2 of the conventional linear compressor, a cylinder block 4 provided with the cylinder 3 and a back cover 6 provided with an inlet 5 are equipped. The cylinder block 4 and the back cover 6 are upheld in the hermetic casing 2 by a main damper 7 and a subsidiary damper 8, so as to absorb a shock (see FIG. 1).
The linear motor 10 is mounted between the cylinder block 4 and the back cover 6, which generates driving force to compress fluid.
The linear motor 10 is divided by a stationary part and a movable part. The stationary part includes an outer core 11, an inner core 12, and a coil 13 with a magnetic field. The movable part includes a magnet 14 that linearly reciprocates by magnetic force around the coil 13, and a magnet frame 15 which the magnet 14 is fastened to.
The piston 16 is connected to the magnet frame 15, which receives linear driving force from the magnet 14, linearly reciprocates in the cylinder 3, and compresses fluid.
In a rear of the piston 16, a flange 17 is formed to be fixed to the magnet frame 15. A main spring 18 is disposed between the flange 17 and the cylinder block 4, and a subsidiary spring 19 is disposed between the flange 17 and the back cover 6, so that the piston 16 is elastically suspended.
The piston 16 is in the shape of a cylinder, which is open at its rear. An inhale passage 20 where fluid is entered is provided therein, and a plurality of inhale ports 21 is provided in its front.
In a front of the piston 16, there is an inhale valve 22 for opening and closing the inhale port 21. Fastened to the piston 16 by a connection member, the inhale valve 22 gets elastically bended, depending on a pressure difference between the inside and the outside of the inhale port 21, thus opening and closing the inhale port 21.
An exhale part 30 is configured in a front of a compression chamber C of the cylinder 3, which discharges compressed fluid.
The exhale part 30 includes an inner exhale cover 32 fastened to the cylinder block 4 and provided with an exhale hole 31, an exhale valve 34 elastically suspended in the inner exhale cover 32 by an exhale spring 33, which opens and closes the compression chamber of the cylinder 3, and an outer exhale cover 35 positioned at a regular interval from an outer surface of the inner exhale cover 32 (see FIG. 2).
An exhale pipe 36 is set in the outer exhale cover 35, which discharges compressed fluid to the outside.
A spring sheet 37 is set in the inner exhale cover 32 to prevent against an abrasion, occurred by a repetitive load from the exhale spring 33.
The spring sheet 37 is mounted in one side of the inner exhale cover 32 as a flat plate, not to touch with an edge of the exhale spring 33, and is made of Teflon.
The exhale spring 33 is a conic coil spring to give the elasticity toward a direction that the exhale valve 34 closes the compression chamber C of the cylinder 3. One edge meets the spring sheet 37, and the other is inserted into a safe portion formed in the exhale valve 34.
The conventional linear compressor operates in the following sequence.
In operation of the linear motor 10, the magnet 14 linearly reciprocates due to the magnetic field around the coil 13 and its interaction, its driving force is delivered to the piston 16 through the magnet frame 15. The piston 16 continuously moves back and forth between the exhale valve 34 of the exhale part 30 and the back cover 6.
When the piston 16 moves toward the exhale part 30, the inhale valve 22 becomes closed by the pressure difference of the inhale passage 20 and the compression chamber C.
As the piston 16 moves forward, fluid in the compression chamber C is compressed, allows the exhale valve 34 to be opened by recovering the elasticity of the exhale spring 33, and is discharged to the outside through the inner exhale cover 32 and the outer exhale cover 33.
When the piston 16 moves backward, the inhale valve 22 becomes opened by the pressure difference of the inhale passage 20 and the compression chamber C.
Fluid in the inhale passage 20 of the piston 16 flows into the compression chamber C through the inhale port 21, and the exhale valve 34 closes the compression chamber C by the elasticity of the exhale spring 33.
As the piston 16 moves back and forth, compressing fluid within the compression chamber C and discharging are repeated.
As the exhale valve 34 is repeatedly opened and closed, the repetitive load is given from the exhale spring 33. The spring sheet 37 prevents the edge of the exhale spring 33 from touching with the inner exhale cover 32, and prevents against the abrasion and a transformation of the exhale spring 33 and the inner exhale cover 32, caused by the repetitive load from the exhale spring.
However, in the linear compressor having the conventional exhale part, as the spring sheet 37 is made of Teflon having a weak intensity, the transformation and the abrasion may be occurred due to the excessive load by the exhale spring 33 or by a condition of a high temperature.
Furthermore, as the spring sheet 37 is formed as the flat plate, only one side of the inner exhale cover 32 is protected. In case that the repetitive load is given to a touching portion of an outer circumference of the exhale spring 33 and the inner exhale cover 32, the abrasion and the transformation cannot be avoided.